The present invention relates to a valve device according to the preamble of the main claim, as it is known from DE 44 02 647 C1. Such a device, in the form of a check valve, for example, is generally known as a hydraulic or pneumatic valve, and is used for a wide variety of applications. A typical application is the blocking or opening (controlled by the valve) of a cooling circuit in a motor vehicle.
Such applications are characterized by the fact that relatively large expanses of the fluid flow channel must be blocked, which requires correspondingly large restoring forces (due to the large pressure application surfaces). It is common practice, particularly in the described context of motor vehicle construction, to use an electromagnetic actuator to actuate the valve, thereby causing the valve tappet to carry out a blocking or opening movement, but the aforementioned large pressure application surfaces nevertheless demand correspondingly large (and accordingly heavy), electromagnetic devices. Apart from the technical manufacturing effort involved, such devices are awkward to install, consume substantial amounts of electrical energy, and are (disadvantageously) heavy.
Therefore, it must be assumed that, particularly when rapid switching times or other dynamic properties of the valve device are not of the greatest importance, the use of “piloted” valves for similar or comparable applications is known from the prior art. Such piloting would further assist the blocking movement of the valve tappet by means of a “pilot pressure” or “pilot force”, so that to this extent the actual size of the actuator can then be smaller.
The object of the present invention is therefore to extend the usability of a species-related valve device, particularly in the form of a check valve for large nominal diameters, and in such context particularly to optimise an actuator system essential for the application of a restoring force in terms of the dimensioning and energy consumption thereof, and thus to provide a valve device that is able to used and installed flexibly and guarantees good operating reliability, but at the same time has a simple construction.